Solid diazo salts



l atenteci Jan. 5, 1937 UNITED STATES PATENT GFFICE bach-on-the-Main,

Germany, assignors to General Aniline Works, Inc., New York, N. Y., a corporation of Delaware N Drawing. Application May 17, 1933, Serial No. 671,590. In Germany May 21, 1932 Claims.

The present invention relates to new solid diazo salts; more particularly it relates to diazo salts containing a free amino group and corresponding probably to the general formula:

wherein Y stands for halogen, n stands for the number 1 or 2, X means an inorganic anion, such as halogen, the radical of sulfate, bisulfate or fluoborate and others, or the radical Me-halogen m+z p being the number 1 or 2, and wherein the benzene nucleus may be further substituted.

'The diazo salts may be obtained by diazotizlng unilaterally 1,4-diaminobenzenes, halogenated in the nucleusand being free from sulfonic acid or carboxylic' acid groups, 1. e. by treating the said 30 1,4-diaminobenzenes with the quantity of mineral acid and nitrous acid, necessary for diazotizing one amino group, and by precipitating the diazo compounds, thus obtained, in a solid form according to known methods.

Morgan and Cleage Ecf. Journal of the Chemical Society, 113, (1918), pages 590 and 596] have transformed 2,6-dichloro-IA-diaminobenzene in dry acetone solution into 2-,6-dichlorobenzene-4- diazo-l-imine by the action of nitrous anhydride. The product, thus obtained, is very unstable. It was not separated in a solid form but, after its formation, it was at once acetylated in the acetone solution and thereby identified.

It could not be foreseen that halogenated 1,4- 5 diamino benzenes could be transformed in a smooth reaction into aminodiazonium salts in the presence of mineral acid and it could, furthermore, not be foreseen whether these monodiazo compounds could easily be precipitated and 50 whetherthey would be stable enough for being used on an industrial scale as dyeing salts.

As is known, it is not possible to perform the mono-diazotization of para-phenylenediamine in a technical manner. Biilow lcf. Berichte der dieutschen chemischen Gesellschaft, 29, (1896),

page 2285] describes the unilateral diazotization of nitro-para-phenylenediamine; but it could not be concluded from this literature reference that it would be possible to transform halogented 1,4- diaminobenzenes into a mono-diazo compound.

The present unilaterally diazotized 1,4-diaminobenzenes may be separated in the form of mineral acid salts, such as chlorides or sulfates, or in the form of stabilized diazo compounds, such as, for instance, zinc chlorideor cadmium chloride-double salts, fluoborates or the different kinds of arylsulionates. All these diazo salts possess a very good stability, even at higher temperatures. It is, therefore, possible to furnish the dyer, for whom it is difiicult or at least laborious to carry out the mono-diazotization of the diamines, with mono-diazo compounds in a stable form ready for use.

These new solid diazonium salts which may be diluted with the usual admixtures and adjusted to the usual commercial form, are of especial value in the ice color industry.

The following examples serve to illustrate the invention, but they are not intended to limit it thereto, the parts being by weight:

(1) 1'77 parts of 2,5-dichloro-lA-diaminobenzene are dissolved or suspended in 270 parts of hydrochloric acid of 32.1% strength and 3500 parts of water and diazotized at 10 C. to C. with a solution of '72 parts of sodium nitrite in 150 parts of water. When the diazotization is finished, the whole is filtered and 820 parts of sodium chloride are added to the filtrate. The diazonium chloride which has separated in a crystalline form and which has the probable formula:

megs...

is filtered with suction and dried at about 40 C. It possesses a very good stability and is easily soluble.

In an analogous manner, there may be obtained the diazonium chlorides of other halogen- 1,4-diaminobenzenes, such as, for instance, of 2,6-dibromoand of 2-chloro-5-methyl-1,4-diaminobenzene.

(2) 177 parts of 2,6-dichloro-1,4-diaminobenzene are diazotized in 158 parts of sulfuric acid of 78% strength and 1600 parts of water at 10 C. to 15 C. with a solution of 72 parts of sodium nitrite in 650 parts of Water. The diazonium sulfate of the following probable formula:

HaliGNz-HSO;

is precipitated from the filtered diazo solution by means of 180 parts of sodium sulfate and 310 parts of sulfuric acid of 78% strength. The Well crystallized salt possesses a very good stability and is easily soluble. It may be adjusted to the usual commercial form by addition of, for instance, anhydrous sodium sulfate or partly dehydrated aluminium sulfate. For this purpose, parts of dry diazonium sulfate are intimately mixed, for instance, with 200 parts of anhydrous sodium sulfate.

In an analogous manner, there may be prepared, for instance, the diazonium sulfates of 2,5-dichloroand '2,6-dibromo-1,4-diaminobenze-ne.

(3) 177 parts of 2,6-dichloro-1,4-diaminobenzene are dissolved or suspended in 270 parts of hydrochloric acid of 32.1% strength and 3500 parts of Water and diazotized at 10 C. to 15 C. with a solution of 72 parts of sodium nitrite in 300 parts of Water. To the diazo solution, there are added 150 parts of a zinc chloride solution of 50% by weight and the diazonium zinc chloride double salt of the following probable formula:

is salted out by addition of sodium chloride,worked up as usual and, if desired, adjusted to the usual commercial form by addition of, for instance, anhydrous sodium sulfate or partly dehydrated aluminium sulfate. The salt is very stable and easily soluble.

The precipitation may also be effected by means of a zinc chloride solution which has a small content of SnCh.

In an analogous manner, there may be obtained the diazonium zinc chloride double salts of other halogen-1,4-diaminobenzenes, for instance, of 2-chloro-, 2-chloro-5-methyland 2- chloro-fi-bromo-1,4-diaminobenzene.

(4) 222 parts of 2-chloro-6-bromo-1,4-diaminobenzene are diazotized as described in Example 3. The diazo compound is precipitated by means of parts of crystallized cadmium chloride and sodium chloride and worked up as usual. The cadmium chloride double salt is very stable. 7

(5) 143 parts of 2-chloro-1,4-diaminobenzene are diazotized in 270 parts of hydrochloric acid of 32.1% strength and 1400 parts of Water at 10 C. to 15 C. with a solution of 72 parts of sodium nitrite in 300 parts of water. The diazo solution is filtered and 280 parts of a sodium fluoborate solution of 44% by weight are added to the filtrate. The diazo compound precipitates in the form of the crystalline fiuoborate. The salt is very stable. It corresponds to the probable formula:

(6) 187 parts of 2-bromo-L4-diaminobenz'ene are diazotized in 145 parts of sulfuric acid of 78% strength and 2800 parts of water at 10? C. to 15 C. with a solution of 72 parts of sodium nitrite in 300 parts of water. To the diazo solution, there are added 740. parts of an aqueous solution of 41% strength of free 1,5-naphthalene disulfonic acid. The Lil-naphthalene disulfonate separates in a crystalline form and is worked up in the usual manner. It possesses a very good stability.

By replacing 1,5-naphthalenedisulfonic acid by 2,6-naphthalenedisulfonic acid, there is obtained in an analogous manner the corresponding 2,6- naphthalenedisulfonate.

(7) 240.5 parts of the sulfate of 2-chloro-1,4- diaminobenzene (obtainable from 1 mol. of chlorophenylenediamine and 1 mol. of sulfuric acid) are suspended in 1924 parts of glacial acetic acid at 15 C. to 20 C. Thereupon, parts of amylnitrite are added, drop'by drop, at 15 C while well stirring, whereby the sulfate of the base is gradually transformed into the diazonium sulfate. Stirring is continued for 2 hours at 15 C. 20 C., the whole is filtered with suction and the solid matter is dried at 40 C.

By addition of ether to the mother liquor, there may be precipitated therefrom a further small quantity of diazonium sulfate.

The diazotization may also be performed in-thefl presence of other organic liquors, for instance, in the presence of benzene.

(s) 275 parts of finely powdered sulfate eras dichloro-1,4-diaminobenzeneare suspended in 2000 parts of carbon tetrachloride. 80 parts of ethylnitrite are introduced into this suspension and the whole is stirred until the diazotization is finished. The diazonium sulfate which has separated, is isolated from the liquor and dried.

(9) 177 parts of 2,6-dichloro-1,4-diamin0benzene are diazotized in'270'parts of hydrochloric acid of 32.1% strength and 3500 parts of water at 10 C. to 15 C. with a solution of 72 parts of sodium nitrite in 300 parts of water. To the diazo solution, there is added a solution of 260 parts of the sodium salt of para-chlorobenzene sulfonic acid in 500 parts of water of about 35 C. Thereby, the diazonium-para-chlorobenesulfonate separates and is Worked up as usual. It corresponds probably to the following formula:

It forms a feebly brown powder. In an analogous manner, there may be prepared, for instance, the chloro-toluene-sulfonate,'

usual. The tin chloride double salt forms a 5 feebl'y brownish powder and corresponds probably to the following formula:

HzN-ONr- -SnClu We claim: 1. The solid diazo salts corresponding to the general formula:

wherein Y stands for halogen, X means an inorganic anion, and Z stands for one of the group consisting of hydrogen, halogen and alkyl, being very stable and easily soluble in water.

2. The solid diazo salts corresponding to the general formula:

wherein Y stands for halogen, X means an inorganic anion, and Z stands for one of the group consisting of hydrogen, halogen and alkyl, being very stable and. easily soluble in water.

3. The solid diazo salts corresponding to the general formula:

wherein X means an inorganic anion, being very stable and easily soluble in water.

4. The solid diazo salt corresponding to the formula: 

